Disk harrow



y 1943. J. P. SEAHOLM Re. 22,327

DISK HARROW Original Filed June- 50, 1939 4 Sheets-Sheet l May 25, 1943. J. P. SEAHOLM DISK HARROW Original File'd June so, 1939 4 Sheets-Shee 2 Jo/.w 7? SEHHOL/V y 5, 1943. J. P. SEAHOLM Re. 22,327

DISK HARROW Original F iled June 30. 1959 4 Sheets-Sheet 4 JZw/v P 654/102 M cw rx e', W

Reissued May 25, 1943 22,327 DISK minnow John P. Seaholm, Moline, 111., assignor to Minneapolis-Moline Power Implement Company,

Minneapolis, Minn., a corporation of Delaware Original No. 2,226,587, dated December 31, 1940, Serial No. 282,091, June 30, 1939. Application for reissue June 26, 1941, SerialNo. 399,873

25 Claims.

This invention relates to improvements in disk harrows.

The primary object of the invention is to provide an improved harrow of the wide cut variety designed to work a maximum width or strip of ground and with means for conveniently reducing the overall width of the harrow for transporting it through gates, along roads and other narrow places. Another object is to provide in a harrow of this kind a novel framework and gang assembly and arrangement wherein the gangs may be outspread to working relation when in use and conveniently adjusted as to their relative angles in this condition; but in which one gang may be uncoupled and connected directly behind the other in tandem relation for transport purposes to thus reduce the width of the harrow at this time to the width of one gang alone. A further object is to provide numerous improvements in draft frame structure and assembly designed to facilitate the operation of adjusting the angle of the gangs, and the operation of changing the harrow from working to transporting conditions.

Another object is to provide a draft frame assembly for the harrow by means of which the draft line may be shifted from its usual central position when the disk gangs are in outspread working positions to a central position with respect to one gang when the other gang is placed in trailing transport position therebehind, to thus maintain proper draft under all conditions and facilitate handling.

Still another and important object is to provide in a harrow of this kind a novel and effective mechanism for adjustably and resiliently resisting the upward thrust produced at the inner ends of the gangs by the reaction of the earth against the angularly disposed disks, to thereby insure a uniform penetration by both inner and outer disks. More particularly it is an object to so design this resisting mechanism that it will be capable of maintaining the gangs as stated but without causing or producing undesirable end thrusts as between the disk units or gangs proper, and thus overcoming objections inherently present in certain harrows as used prior to my invention.

These and other more detailed and specific objects will be disclosed in the course of the following specification, reference being had to the accompanying drawings, in which- Fig. 1 is a plan view'of my improved harrow shown with the gangs at a working angle.

Fig. 2 is an enlarged fragmentaryplan view of aportion of one. disk gang-and draft'frame member, showing the bearing and drag link connec- 'side member, illustrating the guide block for properly aligning the mounting holes for the removable pin connecting these parts.

Fig. 4 is a view similar to: Fig. l but showing one disk gang disconnected from the draft frame prior to being coupled behind the other gang for transport.

Fig. 5 is an enlarged-fragmentary side elevation of the latch means for adjusting and locking the draft frame in various positions.

Fig. 6 is a detail view, partially in rear elevation and partially in vertical section, showing the connection and bearing, between inner and outer sections of each disk gang.

Fig. '7 is a plan view of the harrow in transport position, showing the gangs in aligned relation, front to rear, and showing the draft frame shifted to bring the draft line over to the center of the gangs.

Fig. 8 is a plan view of one disk gang bearing showing the upper bearing sectionremoved and certain-parts in horizontal section.

Fig. 9 is an enlarged cross sectionalong the'line 9-9 1'.

Fig. 10 is an enlarged frontal elevation of acentral portion of the disk gangs, showing the draft'tongue' in cross section, and illustratingthe action of the spring device in resisting upthrust at the inner ends of the disk gangs. 7

i Fig. 11 is an enlarged" end view of" the disk gangs in the transport position shown in Fig. '7'.

Fig. 12 is an enlarged fragmentary section along the line I2l2 in Fig. 4.

It may be noted that this invention has certain features in common with my United States Patent No. 2,226,586 the application for which was copending with the original application, Serial No. 282,091 hereof; such features being further disclosed in my applications Serial No. 341,867 (now Patent 2,266,819) and Serial'No. 338,076, also copending with such original application Serial No. 282,09 1.

Referring now with more particularityto the drawings, A-designates-generally the draft frame for connection forwardly to the draw bar 13 of the tractor (not shown) and C and'Drepresent the respective disk gangs'which are, as shown, each of substantial length so thatintheir outspread'p'ositions the harrowwill work a wide strip of ground} The advantages-of-such a harrow will be obvious, but it will be equally obvious that the gangs will be far too wide to pass through an ordinary gate or road, and it thus becomes necessary to reduce this width when the harrow is transported from field to field. This I accomplish by the structure which will now be set forth in detail.

The draft frame comprises a central, generally fore and aft extended main draft member or tongue I3 provided with means at its frontal end for connection to the aforesaid drawbar B and at its rear end with a transverse, laterally extended coupling l4 made up of upper and lower straps welded or otherwise secured to the tongue. Side bars or side draft bars I5 and I6 are .pivotally mounted at their inner ends by pins or bolts [1 within this coupling I4 and normally extend outwardly therefrom as shown. Said pivots I1 being vertically axised, it will be evident that these draft bars I5 and I6 may swing forwardly and rearwardly in horizontal planes at each side of the tongue I3. Brace bars I8 and I9 are provided for bracing and adjusting these draft bars and are pivotally connected at 20 thereto and extend forwardly in converging relation to points 2I of pivotal connection with a slidable bearing member 22 on the tongue. This bearing member has a tubular portion 23 slidably fitting the tongue I3 and laterally projecting and vertically spaced ears 24 between which the forward ends of the brace bars are received and pivoted by pins or bolts forming the pivots 2| as clearly shown. Inasmuch as lengthwise movement of the bearing member 22 on the tongue is thus readily possible, adjustment of the relative outspread angle of the draft bars I5 and I6 may be made, and for locking the parts in adjusted positions I provide a latch pin 26 slidably mounted in a bracket 21 secured atop the bearing member and supporting the pin for downward engagement under influence of the expansion coil spring 28, with any one of a number of holes 29 provided in the tongue I3 for its reception. A lever 30 is pivoted at 3| on the bracket 21 and engages under a cross stud 32 on the pin 26 so that by swinging this lever upwardly the pin may be raised anddisengaged from the holes in the tongue while angle adjustments are being made. For this purpose the lever is turned angularly upward at its rear end 33 and a pull rope 32 is secured thereto so that the lever may be raised from a remote position such as the seat of the tractor pulling the harrow. A spring 35 normally resists this movement and returns the lever toinoperative position when adjustments have been made. However, I further provide an arm 36 extended upwardly from the bracket 21 and provided with a fork 31 with which a knot 38 in the pull rope 34 may be engaged to hold the pin 25 clear when so desired.

In addition to the foregoing the draft frame also includes a guide or gauge rod 39 having slidable connection by its loop 40 over the brace bar I8 forwardly of a rigidly mounted stop yoke 4| and which is adapted to be releasably and pivotally connected at its rear downwardly turned end 42 with the draft bar I5, as shown.

The disk gangs C and D are substantially identical in construction and differ mainly in the fact that the respective disks 42 and certain other parts are reversed in position for their proper operation. Each gang is made up of a series of these disks 42 mounted upon axles 43 and spaced apart thereon by spacing spools 44 placed over the axles between the disks in the usualmanner. The ends of the axles are of course provided with means for locking the assembly together, and at the inner ends of the gangs this means takes the form of rounded or spherical bumpers 45 as shown.

It will be noted that each disk gang is made up of a pair (or more) of sections disposed end to end and provided with complementary bearing means at their meeting ends. Such bearing means as best shown in Fig. 6 comprises rounded bumpers 46, quite similar to the aforesaid end bumpers 45, secured at the inner ends of the outer gang sections and fitting the concaved and rounded bearing surfaces 41 of the end bearings 48 secured at the outer ends of the inner gang sections. By this arrangement the inner and outer gang sections are permitted complete freedom of differential rotation as the harrow is turned in the field, as will be readily evident. However, it is not contemplated that the gang sections of each unit should have any relative flexibility of movement vertically due to uneven contour of land, and the gangs are eifectively restrained against such action by their connection to the draft frame, as will hereinafter appear.

This sectional gang assembly has been described and claimed in some detail in my aforesaid copending application resulting in United States Patent N 0. 2,226,586.

In the present instance the end bearings 48 are threaded at 49 on the outer ends of the inner gang section axles 43 and are locked against displacement by the insertion of small bolts 50 between th adjacent ends of the said bearings and collars 5| which engage the axles and are locked against rotation thereon. Grooves 52 are provided in the meeting ends of the bearings and collars for the reception of these bolts 50.

Each individual gang section is provided with a pair of bearings 53 which comprise upper and lower sections or member releasably secured together by U-bolts 54 and which hav grooves 55 at their mating faces to define a bearing for the spools 44 mounted between the disks. At the upper ends the U-bolts are passed through angle irons 56 which are locked in place by nuts 51 turned down on the bolts, as clearly shown. The upwardly turned webs 58 of the angle irons thus serve as mountings for bracket arms 59 which are bolted at 60 thereto and extend upwardly and rearwardly between the adjacent disks 42.

At their upper rear portions these arms 59 are provided with slots 6| through which are slidably mounted the scraper bars 62 carrying scraper blades 63 for cleaning the 'concaved sides of the disks. Adjustment levers 64 on these bars 62 permit adjustment of the scrapers toward and away from the disks, and it will be understood that weight. boxes of the usual kind (not here shown) may also be supported from these bracket arms if their use is desired.

The disk gangs thus constructed are arranged rearwardly of, and parallel to, the respective draft bars I5 and I6 and are connected thereto for draft purposes by drag links 65, one of which extends. forwardly from each bearing 53 and is pivotally attached thereto by placing its fiattened rear end 66 between spaced ears 61 on the frontal sides of the bearings and inserting a vertical pin 660. through the ears and link. Forwardly of each disk gang bearing 53 the respectiv draft bars I 5 and I6 are provided with bracket members designated generally at 68 d h of which comprises essentially upper and lower forwardly extended straps 69-1Il, welded or otherwise secured to th upper and lower surfaces of the draft bars. These bracket members are each provided forwardly of the draft bars with vertically aligned and axised bearing openings ll through which are journaled the upwardly turned forward ends 12 of the drag links 65. Cotter pins 13 retain the links in this assembly so that they extend rearwardiy beneath the draft bars I and IE to the disk gangs and connect said gangs to the draft frame.

It will be evident that this mode of connection of the disk gangs C and D to the draft bars l5 and I6 prevents relative vertical displacement between these parts while still allowing the disk gangs to shift freely in an endwise and horizontal direction behind the draft bars. This shifting action is, however, limited tothe point that the disk edges can never strike the draft bars, by means of inner and outer stops or stop lugs l4'|5 turned downwardly from the lower straps 10 of the innermost and outermost bracket members 58 into the path of the drag links 65 as shown. Attention is also directed to the fact that the drag links are curved or offset toward their frontal ends and in a direction away from the adjacent inner disks 42, as designated at 16, so that these disk edges will not strike the drag links in the extreme outwardly shifted position of th gangs.

The next to the outermost bracket members 68 are extended forwardly to receive the bolts forming the rear pivot connections of the brace bars l8l9 and additionally the next inner bearing member on the draft bar I5 is provided with an apertured extension i! for th releasable and pivotal reception of the rear end of the guide rod 35.

In the operation of the harrow as thus far described it will be readily appreciated that in the wide spread and forwardly angled position of the gangs C and D as shown in Fig. l, a wide strip of ground may be worked each trip across'the field. This relative angle of the disk gangs may be varied from a non-working iposition (not shown) but at which they are in axial and transverse alignment, to a position even forwardly of that shown, by simply releasing the latch pin in the manner described and pulling forwardly or rearwardly on the tractor. This action, due to the resistance of the gangs, will then cause a shifting movement of the bearing member 22 on the draft tongue [3 and a corresponding variation of the angle of the gangs.

During such operations the bumpers 45 at the inner ends of the disk gangs remain in abutting relation and the opposing end thrusts upon the respective gangs by their action in the ground causes the gangs to maintain a transverse equilibrium behind the draft frame. However, should either gang meet with less or more resistance due to variations in the texture or characteristics of the soil the gangs may shift endwise behind the draft frame within the limits set by engagement of the drag links 65 with the respective stops 14-15, and this action will in no way interfere with the disking operation.

The bearings 53 and bracket members 68 are so located with respect to each other and to the center of the harrow that, in one working angle of the gangs shown. in Fig. l, the pivot points 66a and 12 of the drag links 65 will be disposed in a plane or line at right angles to the axes of the gangs as represented at XX in Fig. 1. The draft forces are thus transmitted to th disk gangs at right angles to the bearingsur'facesand ings.

in such manner that the bearings are relieved of end thrust which would otherwise be set up by .these forces, and which end thrust is the most troublesome cause of wear in disk harrow bear- This feature is more fully disclosed in my aforesaid Patent No. 2,226,586.

In the present invention I provide, as means for reducing the effective width of the harrow while transporting, the arrangement whereby either disk gang, here shown as the gang C, may be uncoupled, placed immediately behind the othergang to run in tandem formation in the path thereof, and coupled to the remainder of :the harrow. For this purpose the brace bar i8 and guide rod 39 are disconnected from the draft bar I5 and this bar I5 is itself disconnected from the coupling I4, thus freeing the entire gang 0 and draft bar [5 from the harrow, as shown in Fig. 4. The latch pin 26 is then released and the tractor is moved rearwardly, causing the bearing member 22 to slide forwardly on the draft tongue [3 until the pin may be reengaged with a forwardly located opening 18 in the tongue. This action, causing the tongue I3 and brace bar l9 to swing on the pivots l1 and 20, results in the shifting of the frame laterally and over ahead of the single connected gang section D until the draft pin 19 reaches a position in alignment with the front to rear draft line passing through the center of the gang D as clearly shown in Fig. '7. It is thus made possible to pull the single disk gang in an efficient manner and in proper trailing position, and by proper maneuvering of the tractor this gang may be backed up ahead of and parallel to the disconnected gang 0.

The inner and outer bracket arms 59 of the pulling gang D, as it may be termed, are extended rearwardly and downwardly as shown at 8| and are notchedat 82 to receive drag or tow chains 83 which are connected at 84 to fasteners here shown as being eyed pins 85 welded to the inner and outer bracketmembers 68 of the draft bar 15. These chains when thus connected serve to pull along the gang 0 behind the harrow and it will now be evident that the harrow occupies only as much transverse space as one gang alone, and it may therefore be pulled readily through gates, narrow roads, and the like.

When not in use in this transport position of the harrow, the brace bar I8 is folded inwardly alongside the tongue 13 and rests in a hanger 86 secured thereto. The guide rod 39 is then rested over the tongue as shown.

To restore the harrow to working condition the chains 83 are uncoupled and are hooked at their free ends over the extended upper ends of the pins 85 to keep them in the clear as shown in Fig. 10. The harrow is then pulled forward and backed up to a position somewhat alongside the gang 0 and the brace bar I8 is disconnected at 2| and recoupled at 2!! to the draft bar 45. The guide rod 39 is also connected at its rear end 42 to this draft bar. The tractor is now maneuvered until it is possible to reconnect the brace bar 18 at 2| and the tractor is then pulled forward causing the draft forces to pull the disk gang C inwardly toward the other gang D. The stop 4| is so located that the triangular bracing effect of the brace bar and guide rod 39 will hold the draft bar [5 at the proper angle and proper fore and aft position to cause its inner end to properly enter the coupling l4. Also to facilitate this operation the inner end of said idraft bar I5 is provided with a rigidly mounted guide member or block 81 which is tapered on upper and lower sides as indicated at 88 to guide itself into the flared mouth 89 of the coupling. Furthermore, the end of this guide member 81, as best shown in Fig. 3, is rounded at 90 on a radius struck from the center of the connecting pin I! to bear against the adjacent side face 9I of the tongue I3 and thereby gauge the position of the draft bar end to the point that the mounting holes for the pin will fall into proper registry in any angular position of the gangs. The pin I1 may thus be readily inserted to complete the recoupling of the harrow.

The latch pin 26 is then withdrawn from the opening 18 and the harrow is pulled forward, causing the tongue I3 to swing back to a center position between the gangs and along the draft line, and the angle of the gangs may then be set and adjusted as described.

It will be noted that the foregoing adjustments may all be made by maneuvering the tractor and harrow and without attempting to lift or shift the disk gangs by hand. The draft bar I is provided with a leg iron 92 pivotally connected at 93 to normally lie along the frontal side of the bar but which may be swung downwardly at its free end as shown in Fig. 4 to engage the ground and support this bar and the disk gang C while it is being coupled or uncoupled in the manner described. r

In the disking operation there is, as well known, an inward endwise thrust exerted upon the lower working edges of the disks as they travel through the ground. This force, brought to bear upon the bumpers 45 spaced upwardly from the ground by half the diameter of the disks, has a tendency to urge the inner ends of the disk gangs upwardly and, unless counteracted by some means, results in uneven penetration of inner and outer disks.

In accordance with my present invention I provide each draft bar I5 and I6 with an upwardly and rearwardly extended arm 94 between the upper ends of which is arranged a retractile coil spring 95 which exerts an inward pull upon the arms. This action being transmitted to the draft bars I5 and I6 exerts a relatively upward pull or lift upon the outer ends of the bars rocking them slightly on their inner end pivots I1 and, through the drag links 65, causes a downward pressure on the inner ends of the disk gangs C and D to counteract the upthrust thereat.

The spring 95 is hooked at 96 to one arm 94 while at its other end it has an adjusting screw 91 provided with a plug bearing 98 which may be removably inserted in a sleeve 99 secured to the other arm 94. A crank I90 at the end of the screw 9'! permits the tension of the spring to be adjusted to suit the working conditions and of course the plug 98 may be readily removed from the sleeve 99 when the gang C is placed in transporting position, as hereinbefore described.

The arms 94 are located near the inner ends of the draft bars I5 and I6 and may well be formed as extensions of the innermost bracket members 68. In any event, and this is an important point, the arms incline rearwardly to dispose the spring in a plane located rearwardly of the pivots ll of the draft bars. As a result the spring 95 is stretched as the disk gangs C and D are moved forwardly to working angles and the tension of the spring is thus automatically adjusted in accordance with the working angle. In other words, as the end thrust on the gangs is increased, by increase in the working angle,

the additional spring force necessary to counteract the augmented upthrust at the center of the gangs is automatically obtained.

Attention is called to the fact that the draft bars I5 and I6 are not an integral part of the disk gangs C and D but rather that these bars constitute simply draft means for said gangs. The arms 94 being then mounted on the draft bars without direct connections to the gangs, per se, it follows that all the forces exerted by the spring 95, while entirely effective in withstraining the disk gangs against upward displacement, are nevertheless absorbed by the connections at ll of these draft bars with the tongue I3. The bearings of the disk gangs are thus relieved of end thrust from the spring action and the life of the bearings is very materially increased. It will also be seen that by this construction the several disks and gang sections will be controlled and maintained at a uniform depth of soil penetration, and without in any way interfering with the aforesaid freedom of the gang sections for differential rotation, nor with the freedom which the gangs and gang sections have for limited endwise shifting movements by reason of their flexible connections through drag links 65 with the draft bars I5 and. I6.

It is thought that further details as to the construction and operation, as well as the utility of my harrow, will be apparent to those skilled in the art, without further description herein.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is:

1. A disk harrow structure comprising a pair of disk gangs operatively connected and adjustable from wide spread working positions at opposite sides of a medial draft line with their inner ends transversely opposed to tandem positions one behind the other whereby they will traverse a common path of travel, and means for releasably connecting the gangs in tandem position.

2. A disk harrow structure comprising a draft frame, a pair of disk gangs connected to the draft frame and normally disposed in wide spread directly opposite working positions, and one of the said gangs being arranged for adjustment to a position directly behind the other gang, and means independent of the draft frame for connecting the gangs in the tandem position.

3. In a disk harrow, the combination of a draft frame, a pair of disk gangs connected to the said frame and adjustable to wide spread working positions with their inner ends in transversely opposed end to end contact, one of the said gangs being detachable from the draft frame for positioning in tandem relation directly behind the other gang so as to traverse the same path of travel, and means for releasably connecting the gangs in said tandem relation.

4. In a disk harrow, the combination of a draft structure, a pair of disk gangs adjustably connected to the draft structure for operation at opposite sides of a medial draft line and with the axes of the disks intersecting at said draft line, one of the disk gangs being detachable from the draft structure for disposal in tandem position behind the other gang and in fore and aft alignment therewith, and pulling means on the gangs for releasably connecting the same in said tandem positions.

5. A disk harrowcomprising a pair of disk gangs normally "disposed in wide spread working positions and with the axes of the disks intersecting at the medial line between the gangs, a draft frame connected to the gangs, and the said frame being adjustable transversely to shift the draft .line from a central position with respect to both gangs and coincident with respect to said medial line to a central position with respect to one gang.

6. A disk :harrow comprising a pair of disk gangs normallydisposed to travel in laterally ad- .jacentpaths and with their respective innermost disks in abutting contact with each other, a draft frame structure for applying draft forces to the disk gangs normally in a line extending forwardly from the inner ends of the gangs, and :the said draft frame structure being adjustable transversely to shift said draft line to a position forwardly in alignment with a medial portion of one disk gang when the other gang has been removed from its normal relatively lateral position with respect thereto.

'7. A disk harrow comprising a draft member normally disposed in a plane parallel with the line of travel, disk gangs connected to said draft member and extending in opposite directions therefrom; one of the said gangs being detachable and capable of disposal in tandem relation behind the other gang, and means for adjusting the said draft member transversely at its frontal end for shifting the line of draft to a position substantially coinciding with a; fore and aft line through the center of the tandem gangs.

8. A disk harrow comprising a fore and aft extending center draft member, disk gangs pivotally connected with the rear portion of the draft member and normally disposed at working angles at each side thereof, one of the said gangs being detachable'from the draft member for positioning behind and connection to the other gang, and a brace member extended angularly between the last mentioned gang and the draft member and adjustable with respect to the draft member to secure the front end of the latter in a position forwardly of the center of the said other gang.

9. A disk harrow comprising a draft member normally disposed-in a fore and aft position, disk gangs pivotally connected with the rear portion of the draft member and extending laterally to opposite sides therefrom, one of the said gangs being detachable from the draft member for positioning behindtheother gang, a brace member extended angularly between the last, mentioned gang and the draft member and adjustable for securing the forward end of the draft member in a position forwardly of the center of such last mentioned gang, and means for looking the brace member in adjusted positions with respect to the draft member.

lsA disk harrow comprising a draft member, a pair of disk gangs connected to a rear portion of the draft member and adjustable to wide spread working position at opposite sides thereof, brace members extending angularly from the disk gangs and converging forwardly to points of adjustable connection with the draft member, one of the said gangs being detachable from the draft and brace members and movable to a tandem position behind the other gang for transport purposes, means for detachably connecting the gangs when in tandem positions, and the brace member connected to said other gang being adjustable on the draft member to secure the forward end thereof in fore and aft alignmentwith the center of the gangs when in their transport position.

11. A disk harrow comprising a draft tongue having a draft connection at its forward end, draft bars pivotally connected at their inner ends to the rear of the tongue and normally disposed in outwardly extended positions, disk gangs connected to the draft bars, brace members connected to outer portions of the draft bars and extending in converging relation forwardly therefrom, a bearing member connected to the brace members and adjustable forwardly and rearwardly on the tongue, one of the disk gangs and draft bars being detachable from the tongue and brace member for positioning behind and attachment to the other gang during transport of the harrow, and the said bearing member being arranged for adjustment forwardly on the draft member to thereby secure the tongue when the same is swung laterally on its pivotal connection with the connected draft bar to a point at which the draft connection will be disposed in a line perpendicular to the central portion of the disk gangs when in their transport position.

12. In a disk harrow, a longitudinally extending draft tongue, draft bars pivotally connected at inner ends to the tongue and arranged in outspread relation at opposite sides thereof, disk gangs connected to the draft bars, one of the said draft bars being detachable from the tongue to permit disposing the disconnected disk gang behind the other gang, and the connection between this detachable draft bar and the tongue comprising spaced mounting members extended laterally from the tongue, and a coupling member secured to the inner end of the draft bar and tapered toward its inner end to guide the bar into engagement between said mounting members when reconnecting the bar to the tongue.

13. In a disk harrow, a draft tongue, draft bars pivotally connected at inner ends to a rear portion of the tongue, disk gangs connected to the draft bars, one of the said draft bars having a releasable connection with the tongue, and said connection including spaced mounting members extending from one side face of the tongue, a coupling member on the inner end of the draft bar adapted to fit between said coupling members, a removable pin for pivotally connecting the said coupling member with the mounting members, and the inner extremity of the cou- I pling member being rounded on a radius concentric with respect to the axis of the; mounting ,pin for engaging the adjacent side face of the tongue.

14. In a disk harrow, a draft tongue, draft bars connected at inner ends to the tongue and arranged in outspread relation, disk gangs connected to the draft bars, one of said draft bars being detachable from the tongue permitting its connected gang to be arranged in tandem relation behind the other gang, brace bars connected to the draft bars at outwardly spaced points and extending forwardly for connection to the draft tongue, one brace bar being detachab-ly connected to both the tongue and the said detachable draft bar,a guide rod slidably connected to this brace bar and detachably connected to .said detachable draft bar, and a stop on the said tongue, draft bars connected at inner ends to the tongue in outwardly spread positions, disk gangs connected to the draft bars, one of the said bars being detachable from the the tongue permitting the connected gang to be arranged in tandem behind and connected to the other gang for transport purposes, an adjustably connected brace bar and guide rod for connection with the draft bar when the same is disposed substantially in outspread position alongside the tongue, the said brace bar being pivotally connected at a forward point to the tongue, and the par-ts being so constructed and arranged that the brace bar and guide rod will swing the draft bar and gang into proper position for connection to the tongue when the harrow is pulled forwardly.

16. A disk harrow, comprising a draft device, a pair of disk gangs connected to said draft device and normally disposed at opposite side thereof, one of the gangs being detachable from the draft device for arrangement in tandem directly behind the other gang during transport of the barrow and so that the total width of the harrow will not be greater than the length of one gang, and draft chains normally carried by the detachable gang and adapted for connection to the other gang when the gangs are in the tandem positions.

17. A disk harrow, comprising a draft tongue, draf t bars connected to the tongue and normally extending laterally therefrom, disk gangs connected to the draft bars, one of the said bars being detachable from the tongue to permit its connected gang to be arranged in tandem behind the other gang during transport of the harrow, draft members carried by the disk gang which remains connected to the draft tongue, and chains connected to the detachable gang for releasable engagement with the said draft members to act as draft connections between the gangs when in their tandem positions.

18. A disk harrow comprising a draft tongue, draft bars connected to the tongue and normally arranged in outwardly extending positions, disk gangs connected to the draft bars and arranged in parallelism therewith, one of the said draft bars and its connected gang being detachable from the tongue for connection in tandem relation behind the other gang, and means on the said detachable draft bar for supporting the same in position for connection to either the other disk gang or for reconnection to the tongue.

19. In a disk harrow, the combination of a pair of oppositely extending disk gangs, a draft structure for pulling the gangs and including draft bars pivotally connected at inner ends and connected to said gangs, one of the draft bars and connected gang being detachable from the draft structure for arrangement behind the other gang in tandem relation, arms supported by inner portions of the draft bars, a spring connecting the arm for exerting vertical force on the gangs, and the said spring being detachable from one of the arms when the disk gangs are arranged in tandem relation.

20. In a disk harrow, a pair of oppositely extending disk gangs, draft means including a pair of horizontal draft members extending longitudinally of and forwardly with respect to the respective gangs, spring means connecting the draft members and tending to resist displacement thereof from a horizontal plane, and links connecting the gangs to the respective draft members, said links being operative to maintain relative vertical positions of the gangs and draft members while permitting limited endwise movements of the gangs with respect to the draft members.

21. In a disk harrow, oppositely extending gangs, oppositely extending draft bars disposed in parallelism with the respective gangs, draft elements connecting'the gangs and draft bars and having freedom for movement to permit endwise shifting of the gangs with respect to the bars, and spring means connecting the draft bars and operative therethrough and through said draft elements to resist upthrust at inner ends of the gangs.

22. In a disk harrow, a draft frame including a pair of outwardly extending draft bar pivotally associated at their inner ends for relative angling adjustment, disk gangs disposed rearwardly of the bars and connected thereto by links havin freedom for limited oscillating movement to thereby permit endwise shifting of the gangs with respect to the draft bars, and force exerting spring means operatively connecting the draft bars to resist upthrust imparted to corresponding ends thereof by the disk gangs through said links.

23. In a disk harrow, a draft frame including a pair of outwardly extending draft bars pivot ally associated at their inner ends for relative angling adjustment, disk gangs disposed rear- 1 wardly of the bars and connected thereto by draft bars extending outwardly from the tongue and pivotally secured at their inner ends thereto for angling adjustment in a horizontal plane, disk gangs disposed behind the respective draft bars and for attachment thereto for angling adjustment therewith, links connecting the gangs and bars and providing connections permitting endwise shifting of the gangs with respect to the bars, and resilient means connecting the draft bars in a manner to counteract upthrust imparted to ends thereof by the disk gangs through the said connecting links.

25. In a harrow, a draft tongue, a pair of draft bars extending outwardly from the tongue and pivotally secured at their inner ends thereto for angling adjustment in a horizontal plane, disk gangs disposed behind the respective draft, bars and for attachment thereto for angling adjustment therewith, links connecting the gangs and bars and providing connections permitting endwise shifting of the gangs with respect t the bars, and yieldable means for resisting the upthrust created at corresponding ends of the gangs by the reaction of earth to the operation of the disks therein.

JOHN P. SEAHOLM. 

